Reprinted with permission from BoatersWorld.com

There’s a good reason many animals hibernate during the winter. Preparing for long periods of inactivity and seeking protection against extreme climatic conditions are necessary steps for survival. It’s no different when it comes to your boat and motor. Proper “winterization” is a must for protecting your craft, and ensuring that it’s in ship-shape condition when spring rolls around. Here are some valuable tips for safeguarding your valuable recreational asset during the “off season.”

Fill ‘Er Up

Be sure to fill your boat’s fuel tank to capacity (allowing just a little bit of room for expansion) and add stabilizer, prior to stowing it away for the winter. Failing to do so will allow air into the tank, which can condense on the sides as the temperature changes causing corrosion and clogging over time. Turn off all fuel valves, and use duct tape to seal off any through-hull exhaust ports. This will also help prevent potentially harmful internal condensation. In addition to these steps, remember to replace your boat’s fuel filter and water separator.

Protect Your Engine

Oil tends to settle on the bottom of the engine block when a boat is not being used, exposing the pistons and valves to air, humidity and other corrosive materials. To guard against this situation, remove the spark plugs and spray ”fogging oil” inside the carburetor and down the spark plug holes. Then replace the plugs without reconnecting the wires. This will provide a long-lasting protective coating for these essential engine parts.

It’s also important to replace your engine’s old gear oil with fresh oil. Dispose of any used oil at an authorized recycling center. The lower unit gear case lubricant on outboards and inboard/outdrive engines should also be flushed and changed. This will eliminate water from the system and provide better overall protection for key internal parts. Also replace oil filters on inboard and outdrive engines.

Use the Right AntiFreeze

If your engine uses coolant, drain the existing fluid from the engine block and manifolds and replace with a non-toxic, propylene glycol base antifreeze. Despite pressure from the EPA and other environmental organizations, many antifreeze products still feature an ethylene glycol base, which is known to release toxins into the water. Not only is the propylene glycol variety better for the environment, most manufacturers say this type of antifreeze is better for your engine as well.

Remove Your Battery, Electronics, and Safety Devices

If you are planning on storing your boat out of the water, disconnect your battery and store it at home for easier maintenance and better protection against theft. Removing your battery is not recommended, however, if your boat will be remaining in the water during the winter period. Boats left in the water should have the battery onboard and functioning so the bilge pump will continue to function if needed. If you will be taking your battery off the boat, make sure it is fully charged prior to stowing it away. Be sure to maintain the charge throughout the storage period (to avoid freezing), and replenish the water level periodically. It’s also wise to remove all of your sensitive and valuable marine electronics from the boat for the winter, and to store this equipment in a safe place at home. This will help prevent theft and possible damage caused by shifts in temperature and humidity. Winterization also presents a perfect opportunity to remove items like dock lines, floatation devices, flares, fire extinguishers from the boat for inspection and possible replacement.

Check Your Prop

Take this opportunity to check your boat’s propeller and hub. Your prop blades may have become bent or nicked over the course of the boating season, which can diminish overall performance. The hub may also be have sustained extensive wear and may even be close to being stripped. If this kind of damage has occurred, you should replace the propeller and make any necessary repairs during the winterization process. This way, you won’t have to worry about these things come springtime.

Clean, Clean, Clean Your Boat

Before putting your boat to bed for the winter, be sure to give it a good cleaning inside and out. If you store your boat with dirt, scum, barnacles and the like on the exterior, these impurities will be even harder to remove in the spring. Once the exterior of your boat is sparkly clean, apply a quality polish to create a protective barrier against dirt and dust. When cleaning the interior, don’t forget the teak, vinyl and carpet. These are areas where dirt, combined with moisture can breed mildew, especially in the dark environment of a covered boat with little or no ventilation. To help keep your boat free of mildew, you may want to install a dehumidifier or use one of the odor/moisture “absorbers” offered by various manufacturers. Turn any cushions up on edge so that air can circulate around them, or better yet, remove them from the boat for storage in a climate controlled area. Also remember to clean any bilges and drain any existing water. Remove all drain plugs and put them in a place where they’ll be easy to find when you’re ready to bring your boat out of winter hibernation. Clean any bilges on your boat too, and protect them with a coating of moisture displacing lubricant and a little antifreeze.

Empty Your Head

If your boat is equipped with a marine head, make sure you pump out the holding tank at an approved facility prior to winter storage. Add fresh water to the bowl and flush several times. Use a cleaner approved for your type of system, and let the solution sit for a few minutes before adding more fresh water and pumping it out again. Follow this process by adding antifreeze (alcohol-based if this type of solution won’t damage the system) and pump the coolant through the hoses, holding tank, Y-valve, macerator and discharge hose.

Put it on the Block

If you own a trailer boat, it’s a good idea to put the boat and trailer up on a block for winter to take the pressure off the tires. You may even want to remove the trailer tires to help discourage theft while the boat is in long-term storage. Take the opportunity to inspect the trailer tires for wear and tear. Also grease the wheel bearings, replacing them if necessary.

Go Undercover

Whether you’ll be storing your boat outside, or inside a garage or structure, your craft should be covered. If it will be outdoors and exposed to elements, you’ll need a storage cover to protect the interior of the boat from the harsh winter environment. Even if your boat will be kept in dry storage, a cover of some kind is recommended to guard the interior against dirt, dust, pests and bird droppings. For outdoor storage, a quality 8- to 10-ounce cotton canvas boat cover is ideal. Make sure that the cover properly sized and fitted for your particular boat model. It should also be supported so water will run off the cover and not accumulate in pockets. If your boat will be kept in dry storage for the winter, the waterproof quality and strength of the cover will not be important factors. In this situation, the main concern is keeping dust and other particulate matter from gathering on your boat, so nearly any type of tarp or cover will get the job done. A fitted cover is preferred however, because it will also keep mice, rats and other undesirables from seeking refuge in your boat and damaging the interior.

If conditions will be extreme, you may want to consider “shrink-wrapping” your boat instead of using a standard cover. Only a shrink-wrap cover provides 100 percent waterproof protection, is impossible to blow off, and can withstand heavy loads of snow or rain. Shrink-wrapping your boat can be a do it yourself job, but it requires proper tools, materials and instructions. Complete shrink-wrap kits are available through most boat product retailers.

Additional miscellaneous winterization tasks:

• Inspect steering systems, including tiller-steering friction fittings on outboards, and tighten them if necessary.
• Grease all external fittings on stern drives.
• Check bulbs and electrical contacts on the plugs, as well as sockets where the bulbs screw in. Use a moisture displacing lubricant to spray the contact points, and wrap keep the plugs dry by wrapping them with electrical tape.